iOS 4 is the
fourth major release of the
iOS mobile operating system
A mobile operating system is an operating system for mobile phones, tablet computer, tablets, smartwatches, smartglasses, or other non-laptop personal computing, personal mobile computing devices. While computers such as typical laptops are "mobi ...
developed by
Apple Inc., being the successor to
iPhone OS 3. It was announced at the Apple Special Event on April 8, 2010, and was released on June 21, 2010. iOS 4 is the first iOS version issued under the "iOS" rebranding, dropping the "iPhone OS" naming convention of previous versions. It was succeeded by
iOS 5 on October 12, 2011.
iOS 4 introduced folders on the home screen, significantly increasing the number of apps that can be displayed. Support for custom wallpapers was also added, although limited to newer devices due to animation performance requirements. The operating system also added a multitasking feature, letting apps dealing with
Internet calling,
location and audio playback function in the background, whereas a similar but more restricted "Fast App Switching" technology enabled any app to be left inactive in the background while users switch to other apps. iOS 4 also added a system-wide spell checking feature, enabled
iBooks on iPhone, unified the
Mail
The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...
inbox to combine content from different email providers, and introduced both
Game Center for social gaming and
FaceTime for
video calling.
The iOS 4 update introduced performance and battery problems on
iPhone 3G devices, with Apple investigating the matter and promising then-upcoming updates. However, the company became the subject of a lawsuit from a unsatisfied customer over the issues. Around the same time, the release of
iPhone 4 and its subsequent
antenna problems made Apple focus on unsuccessfully attempting to
patch the issues with software updates.
This is also the final iOS operating system to have, on iPhones, an iPod app for music and videos; starting with iOS 5, iPhones have the same separate Music and Videos apps as do
iPod Touch and
iPad
The iPad is a brand of iOS and iPadOS-based tablet computers that are developed by Apple Inc. The iPad was conceived before the related iPhone but the iPhone was developed and released first. Speculation about the development, operati ...
models.
Apps
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iBooks
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Game Center
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FaceTime
History
iPhone OS 4 was introduced at the Apple Special Event on April 8, 2010. At the
WWDC keynote address on June 7, 2010, it was renamed to iOS 4 in order to be more inclusive to the iPod Touch and iPad.
iOS 4 was officially released on June 21, 2010.
Updates
System features
Home screen
iOS 4 raised the maximum number of home screen apps from 180 to 2,160 due to the addition of folders. These folders would automatically be named based on the containing apps' respective
App Store category. The ability to add custom wallpapers to the home screen was also added, though the feature was notably absent from
iPhone 3G and the second-generation
iPod Touch due to poor performance of icon animations.
Multitasking
iOS 4 introduced multitasking. The feature allowed users to switch between apps instantly by double-clicking the home button. It was implemented in such a way that did not cause excessive battery drain. Multitasking was limited to apps dealing with
Internet calling,
location, and audio playback, while a similar "Fast App Switching" technology meant users could leave an app and enter another, with the original app remaining in the background until the user returns.
This feature was notably absent from iPhone 3G and the second-generation iPod Touch due to performance issues.
Spell check
iOS 4 introduced a
spell checking feature that underlined misspelled words in red. Tapping on the word would provide a pop-up with a recommended replacement.
Camera
The Camera app now supports 5x digital zoom.
App features
iBooks
iOS 4 introduced iPhone and iPod Touch support in
iBooks, which was already included on iPad. Though not a default app, it was available through
App Store.
Mail
The
Mail
The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...
app featured a unified inbox on iOS 4, allowing users to see messages from all of their email accounts displayed together in a single inbox. It also gained support for
MobileMe e-mail aliases and multiple
Exchange accounts for business users.
Game Center
iOS 4.1 added a new app called
Game Center, an online multiplayer social gaming network, which allows users to invite friends to play games and to compare their scores on a leaderboard.
It was not available on the
iPhone 3G.
FaceTime
iOS 4 introduced
FaceTime, a
videotelephony app that uses the device's camera to allow the user to make video calls with other FaceTime users. This feature was absent from the
iPhone 3G, second-generation
iPod Touch,
iPhone 3GS, and third-generation iPod Touch due to the lack of required features, such as a front-facing camera.
Safari
The
Safari mobile
web browser
A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on ...
on iOS 4 added
Bing as a search option in addition to
Google
Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...
and
Yahoo!
Yahoo! (, styled yahoo''!'' in its logo) is an American web services provider. It is headquartered in Sunnyvale, California and operated by the namesake company Yahoo! Inc. (2017–present), Yahoo Inc., which is 90% owned by investment funds ma ...
.
Beginning with iOS 4.2.1, specific words or phrases on a page could be searched.
Problems
Performance and battery issues
iPhone 3G users reported performance and battery issues after upgrading to iOS 4. Apple started an investigation of the matter in July 2010. In November, Apple was sued for the issues, with an unsatisfied customer alleging "violating the Consumer Legal Remedies Act, unfair business practices, and false and deceptive advertising", with further allegations that Apple knew its software would cause problems on older models. Apple never responded to the allegations, but wrote in a reply to another unsatisfied customer in August 2010 that updates were "coming soon".
Alarm clock
In all versions of iOS 4, the alarm clock in the clock app had a problem in DST when it would go off an hour too early or too late.
Antenna problems
Upon its release, some
iPhone 4 users reported having technical problems with the phone's antennas. Apple attempted to fix the issue in software with iOS 4.0.1, but failed to do so.
Supported devices
The
first-generation iPhone and the
first-generation iPod Touch cannot run iOS 4 and above due to hardware limitations, though the
iPhone 3G did receive iOS 4, despite it having the same processor as the
iPhone 2G. This marked the first time Apple dropped support for older devices.
iPhone
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iPhone 3G
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iPhone 3GS
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iPhone 4
iPod Touch
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iPod Touch (2nd generation)
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iPod Touch (3rd generation)
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iPod Touch (4th generation)
iPad
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iPad (1st generation)
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iPad 2
Apple TV
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Apple TV (2nd generation)
References
External links
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{{Apple
*4
2010 software
Products introduced in 2010
Mobile operating systems
Tablet operating systems
Proprietary operating systems